U+27FA Long Left Right Double Arrow
U+27FA was added in Unicode version 3.2 in 2002. It belongs to the block
This character is a Math Symbol and is commonly used, that is, in no specific script.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. The word that U+27FA forms with similar adjacent characters prevents a line break inside it.
Wikipedia ma następujące informacje na temat tej współrzędnej kodowej:
In logic and related fields such as mathematics and philosophy, "if and only if" (often shortened as "iff") is paraphrased by the biconditional, a logical connective between statements. The biconditional is true in two cases, where either both statements are true or both are false. The connective is biconditional (a statement of material equivalence), and can be likened to the standard material conditional ("only if", equal to "if ... then") combined with its reverse ("if"); hence the name. The result is that the truth of either one of the connected statements requires the truth of the other (i.e. either both statements are true, or both are false), though it is controversial whether the connective thus defined is properly rendered by the English "if and only if"—with its pre-existing meaning. For example, P if and only if Q means that P is true whenever Q is true, and the only case in which P is true is if Q is also true, whereas in the case of P if Q, there could be other scenarios where P is true and Q is false.
In writing, phrases commonly used as alternatives to P "if and only if" Q include: Q is necessary and sufficient for P, for P it is necessary and sufficient that Q, P is equivalent (or materially equivalent) to Q (compare with material implication), P precisely if Q, P precisely (or exactly) when Q, P exactly in case Q, and P just in case Q. Some authors regard "iff" as unsuitable in formal writing; others consider it a "borderline case" and tolerate its use. In logical formulae, logical symbols, such as and , are used instead of these phrases; see § Notation below.
Reprezentacje
System | Reprezentacje |
---|---|
Nº | 10234 |
UTF-8 | E2 9F BA |
UTF-16 | 27 FA |
UTF-32 | 00 00 27 FA |
Adres URL cytowany | %E2%9F%BA |
HTML hex reference | ⟺ |
Błędne windows-1252 Mojibake | ⟺ |
HTML named entity | ⟺ |
HTML named entity | ⟺ |
HTML named entity | ⟺ |
Kodowanie: GB18030 (hex bajtów) | 81 37 D4 38 |
LATEX | \Longleftrightarrow |
Gdzie indziej
Kompletny opis
Właściwość | Wartość |
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3.2 (2002) | |
LONG LEFT RIGHT DOUBLE ARROW | |
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Common | |
Other Neutral | |
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0 | |
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NA | |
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Yes | |
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neutral | |
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not a number | |
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R |